Fluid tight electric connector

ABSTRACT

Tight electric connector formed of two connection members having each an insulating plug housed in a casing and projecting beyond the casing end surface, a stud embedded into said plug and projecting beyond the end surface of said plug, and an annular recess between said plug and said casing forming a space for the flow of the plug insulating material, occurring when the two connection members are pressed against each other.

United States Patent Harbonn et al. [4 1 Sept. 19, 1972 [54] FLUID TIGHTELECTRIC 3,478,298 11/1969 Nelson ..339/61 M CONNECTOR FOREIGN PATENTS0R APPLICATIONS [72] Inventors: Jacques Harbonn, Jouars Ponchartrain;Jacques Garnier, Le Chesnay, 6,713,298 4/1969 Netherlands ..339/60 Mboth of France 1,554,320 12/1968 France ..339/48 [73] Assign: smut mealsin Pemk des Cub 1,033,752 7/1958 Germany .339/48 bur-ants e1Lubriflants, Rueil Malmaison Hams de Seine. France PrimaryExaminer-Joseph H. MCGlynn A C 8L A t 1' 221 Filed: 06.2,1970 [21] Appl.No.: 77,522 [57] ABSTRACT Tight electric connector formed of twoconnection [30] Foreign Application Priority Data members having each aninsulating plug housed in a 0 t. i 196 F 4 casing and projecting beyondthe casing end surface. a c 8 9 tame 6934 85 stud embedded into saidplug and projecting beyond 52 us. C1. ..339/48, 339/60 R, 339/94 R theend surface 0f said fland an annular 511 int. Cl. ..110lr 13/22 betweenSaid P s and said casing forming a space for 581 Field of Search..339l47-49,59-61, the flow of the p g ing material. rring 339/94 whenthe two connection members are pressed against each other.

6 Refe Cited [5 1 17 Claims, 10 Drawing Figures UNITED STATES PATENTS2,195,189 3/1940 Sauer ..339/61 L PAIENTEBsEP 19 m2 SHEET 2 0f 3 FIGAINVENTORS JACQUES HARBONN JACQUES GARNIER E a wQ BY CYQQS, Antoneui,Stewed. 4

ATTORNEYS SBEEI 3 BF 3 INVENTORS JACQUES HAR N JACQUES GAR ATTORNEYSPNENTEDSEP 19 m2 FLUID TIGHT ELECTRIC CONNECTOR This invention relatesto a fluid tight electric connector of a new type providing for thetight connection between two electrical circuits placed in a fluidmedium, particularly in a liquid medium which may be electricallyconducting.

The electric connectors proposed up to now generally comprise twocomplementary members coated with or consisting of an elastomer. At thesurface of said elastomer are placed electric studs or contact elements.Centering devices or interpenetrating plugs of complementary shapes ofthe two connection members provide an accurate positioning of thecorresponding contact elements of said connection members. By bringingcloser to each other the two connection members of the connector, forexample by screwing of a threaded ring or of a screw, there isestablished the electric connection between the contact elements, whilea certain flow of the elastomer provide for the simultaneous contact ofseveral studs. It happens that the elastomer flow also ensures a goodsealing about each contact element or even of the whole connector. Thesedevices are generally suitable when the connection members are of smallsize, the two connection members being then easily and with sufficientaccuracy, positioned with respect to each other. The assembling of thetwo connection members is usually made by hand and the pressing forcesare relatively small and may reach a maximum of a few kilograms.

In the case where the connection members to be assembled are very heavyand of a large size, e. g. of about one meter, provided with electriccontact elements, the plugs or connectors of the above type are nolonger satisfactory. In fact, in such a case, the clearances in themechanical assembling reach values higher than one millimeter and do notpermit a sufficiently accurate positioning of the two complementarymembers of the connector. It is therefore not possible to make use ofinterpenetrating contactors or of rigorous centering devices forpositioning in front of each other the electric contact studs of eachconnector element. Moreover the pressing force on the connection membersbeing very high, e. g several hundreds of kilograms, results in a flowof the elastomer which is difficult to control and it has been observedthat the electric connections were not always properly established.

Repeated experiments have lead to the tentative explanation that thesubstantially uncontrolled flow of the elastomer was responsible, inconnectors of the prior art, for the spacing of the electric contactelements and it is therefore an object of this invention to provide anew tight electric connector having well defined size characteristics sothat, during the pressing of the connection members, the flow of adeformable insulating material such as an elastomer performssimultaneously the establishment of the electric connections between thecontact elements, a good electrical insulation and a good sealing abouteach of said contact elements.

It is a main object of the invention to provide a new tight electricconnector which may operate even in a liquid conducting medium.

It is another object of the invention to define the shape and sizecharacteristics of an electric connector of the above-mentioned typewhich may be operated under normal conditions when the connectionmembers to be assembled are of a large size.

It is still another object of the invention to provide an electricconnector of the above-defined type which may withstand high pressingforces.

These objects are attained by the tight connector of this inventionconsisting of at least one pair of connection members each formed of acasing housing a plug of substantially incompressible deformableinsulating material comprising a conducting stud projecting outside theplug above the free surface thereof, the electric connection beingachieved by mere application on each other of the studs of theconnection members in a position of closeness of the latter, by pressingagainst each other their respective deformable plugs, wherein the freesurface of the deformable plug of each connection member protrudes fromits housing above the edge thereof and wherein a recess is arrangedaround the plug in its housing, close to the edge thereof, leaving aspace for the flow of said deformable material when the two connectionmembers are pressed against each other, thereby ensuring the sealing andthe electric insulation around each conducting stud.

The invention will be better understood from the following descriptionof non-limitative embodiments given by way of examples and illustratedby the accompanying drawings wherein FIG. 1 illustrates an example ofuse of an electric connector according to the present invention,

FIG. 1A diagrammatically shows a distribution of the clearances duringthe assembling of large sized members FIG. 2 shows one embodiment ofconnector according to the invention,

FIGS. 3 to 6 illustrate the operation of assembling the two members ofthe connector of FIG. 2,

FIG. 7 illustrates a variant of assembling the two members of theconnector of FIG. 2,

FIG. 8 shows another embodiment of connector according to the invention,and

FIG. 9 is a variant of the connector of FIG. 8.

FIG. 1, to which we will refer again, shows an example of use of aconnector of this invention on a submerged oil well head.

Reference 1 indicates the top block of the oil well head submerged atgreat depth, for example 200 or 300 meters on which operations are to beperformed with the aid of a special device therefor diagrammaticallyshown with reference 2.

The connection of device 2 to the top of the well head 1 is, forexample, carried out in a known manner, by means of a coupling 3 securedon the end of device This connection must allow the establishment ofelectric connections diagrammatically shown with reference 4, saidelectric connections being provided, for example, in order to ensure thecontinuity of the remote control circuits for actuation devices presenton the well head or of telemetering circuits etc.

It is clearly apparent that, due to the large size and consequently thehigh weight of the members to be assembled on the one hand and to therequirement of performance of the assembling operation through meansremotely controlled from a floating installation (not shown in thefigure), on the other hand, it is necessary to suffer, between thecomplementary parts of the connection members, assembling clearanceswhich may be as large as l millimeter and sometimes more.

Accordingly there is to be observed an inaccurate line up of the membersto assemble or a bad parallelism of the contact surfaces, even in somecases both of these drawbacks as diagrammatically shown in FIG. IA.

FIG. 2 illustrates an embodiment of connector according to thisinvention. The connector comprises two identical connection members,only one of which is shown in FIG. 2.

This element to which is given the general reference 4, comprises acasing or rigid body 5 of any external shape adapted to the conditionsof use of the connector.

Inside the body 5 is a housing 6 wherein is placed a plug 7 made of adeformable insulating material such as elastomer and which projects by aheight In above the outer surface of the body 5. A diameter reduction 9of said plug 7 is provided at its upper part thus forming an annulargroove or recess 10 between the plug 7 and the housing 6.

A stud or electrically conducting element I1 is partially driven in theplug 7 and projects by a height e above the plug surface. A flexibleconductor 12 for the current supply is connected to stud 11 through anyknown means.

The size characteristics of said connection member which are necessaryfor a proper operation are the following:

a. the plug 7 of incompressible elastomer must not be prestressed whenplaced in position into the bore 6 of body 5 and the clearance betweenthe diameter of the housing or bore 6 and the plug diameter must be from0 to 0.1 millimeter preferably between 0 and 0.05 mm.

b. the ratio elh must be between 1% and V. and

/preferably close to 95.

c. the volume of the annular groove 10 must be at leaSt equal to thevolume of the protruding portion of plug 7.

The selection of the elastomer is not critical, but the best resultshave been obtained with the use of an incompressible elastomer having asufficient hardness i.e hardness degree in shore units in the range from50 to 75, preferably from 60 to 65.

Moreover, as it will be apparent from the description of the operationof a connector according to this invention, the height h of theelastomer above the connector body, is chosen at least equal to one halfof the maximum clearance m (FIG. 1A) acceptable between the opposedsurfaces of the members to be assembled.

FIGS. 3, 4 and 5 illustrate the operation of the embodiment of theinvention shown in FIG. 1.

In FIG. 3 members 4 and 4a of the connector are positioned and fixedrespectively in the top block 1 of the well head and in the coupling 3.Of course the bodies 5 and 5a of the connection members might beoptionally omitted and the plugs 7 and 70 directly housed in therespective cavities of the top block 1 of the well head and of coupling3.

As shown in FIG. 4, when the coupling 3 is brought closer to the topblock 1, the end surfaces 13 and 13a of studs II and 11a come intocontact, thereby establishing the electrical connection. The surfaces 13and 130 are so designed as to be large enough, in spite of anymisalignment of the two connector members resulting from the assemblingtolerances, for ensuring a contact zone of a sufficient surface betweenstuds 11 and lla,giving passage to the electric current without abnormalheating.

The coupling 3 is brought closer and closer to the well head until theend surface 14 thereof comes into contact with the end surface 15 of thetop block I of the well head, as shown in FIG. 5. The correspondingpressing of the connection members against each other results in theflow of the elastomer of plugs 7 and 7a, which is made easier by theprovision of recesses or grooves 10 and 10a. The elastomer thus forms asealing ring providing, in addition, a good electrical insulation aboutstuds 11 and 11a.

FIG. 6 illustrates the case where, as a result of the acceptedtolerances, the two end surfaces of the members to be assembled are notparallel. In such a case even after pressing of the members against eachother, it still remains a slight clearance m which is lower than 2h, 1:being (FIG. 2) the protrusion of projection height of the elastomer plugabove the connector body. Accordingly as shown in FIG. 6, there is stillachieved a sufficient flow of the elastomer for ensuring the insulationand sealing about studs 1 l and 1 In.

As it is apparent from the above description, a connector according tothis invention may be used for establishing electrical connectionsbetween elements immersed in a liquid medium, even electricallyconducting.

FIG. 7 illustrates a preferred embodiment of a connector according tothe invention. At least one of the connection members, e.g. 4a in FIG.7, is rigidly locked onto coupling 3 by means of any known device suchas an elastic stop ring of the circlip type 16, whereas the body 5 ofthe other member 4 may slide into the bore 17 of top block I, theprotruding portion of member 4 with respect to block I being limited bya circlip 19, cooperating with a shoulder 20 of body 5. An elasticdevice 18, shown in the drawing as a spring, is interposed between thebody 5 and the bottom of bore I7.

This elastic device is adapted to exert on the body 5 of element 4 aforce substantially equal to the pressing force exerted for assemblingmembers 3 and 4. Any clearance m between members 1 and 3 to be assembledis completely, balanced by the only sliding of member 4, if smaller thanthe sum of the protrusion height C, of body 5a of member 4a with respectto coupling 3 (which is non-existent in the embodiment of FIG. 7) and ofthe protrusion height C, of body 5 of member 4 with respect to top block1 when the elastic device is not compressed. The operation of theconnector will always be convenient as long as clearance m is lower orat most equal to C, C, +2h,h being the protrusion height of elastomerplugs 7 and 7a respectively with respect to bodies 5 and 5a.

In practice, the selected height C, is about I millimeter and the heighth about I to L5 mm for members to be assembled having sizes of the orderof one meter, on which are exerted pressing forces in the range of fromabout one hundred of kilograms to about one ton, the maximum acceptableclearance between surfaces 14 and 15 of members 1 and 3 being thus ofabout 4 mm, which limit is in fact never reached.

FIG. 8 shows another preferred embodiment of con nector according tothis invention.

It has been observed in practice that the flow of the elastomer takes avery prominent part. Besides, it has been established, by experience,that, when using studs of a thickness e, sticken on the surface of theplug, the obtained results are not satisfactory. Due to the highpressing forces a rapid deterioration of the elastomer plug, eg by tear,has been observed. When using cylindrical studs partially driven in theelastomer plug such as those shown in FIG. 2, the flow of the elastomertends to separate the studs which have to come into contact whenpressing on the connection members. This phenomenon is due partly to theflow of the elastomer which under the high pressing forces appliedthereon, comes to a position where it is interposed between the contactsurfaces of the studs, and partly to the cylindrical shape of the studswhich does not provide for an efiicient anchoring thereof in theelastomer plugs, thus making possible the flow of the whole mass ofelastomer surrounding the cylindrical surface of the studs.

By experience it has been observed that the stud shape illustrated inFIG. 8, comprising a conical portion with an increasing diameter towardsthe inside of the plug, gives the best results.

In this embodiment the plug is manufactured by direct vulcanization onthe stud and the groove is obtained by machining a chamfered edge onbody 5. As shown in said figure the elastic device 18 may consist of apile of so-called Belleville" spring washers.

FIG. 9 shows an alternative embodiment of FIG. 8 with the surfaces ofstuds ll and 11a establishing the electrical contact. The stud 11 has aplane contact surface and the stud 110 has a conical contact surfacewhich can be impressed in stud 11. The stud 11 may for example be madeof lead and stud 11a of an aluminum alloy well known in the art underreference AG It will be understood that, while there has been givenherein certain specific examples of the practice of this invention, itis not intended thereby to have this invention limited to orcircumscribed by the specific details of materials, sizes, proportionsor conditions herein specified in view of the fact that the inventionmay be modified according to individual preference or conditions withoutnecessarily departing from the spirit and scope thereof, andconsequently such modifications are properly, equitably and intended tobe within the full range of equivalence of the appended claims.

What we claim as this invention is:

l. A tight electric connector comprising two connection elements, eachhaving at least one conducting stud embedded in a plug of deformable andsubstantially incompressible insulating material, the conducting studprotruding from the plug free surface, the electrical connectionresulting from the contacting of the conducting studs at a closeposition of said connection elements, each stud being provided with anindividual housing for the plug in which said stud is embedded, the freesurface of the deformable plug protruding from its housing above theedge thereof and having a recess arranged at the periphery of the plugclose to and extending below the edge of the housing to provide for theflow of said deformable material both into the recess and about the studas a result of the pressing of said two connection elements against eachother such that a seal and electrical insulation is provided about eachconducting stud.

2. Tight electric connector according to claim 1, the plug wherein ismade of substantially incompressible elastomer whose hardness degree,expressed in shore units, is between 50 and 75.

3. Tight electric connector according to claim 1 wherein the plug ismade of substantially incompressible elastomer whose hardness degree,expressed in shore units, is between 60 and 65.

4. Tight electric connector according to claim 1, wherein said recess isformed by a diameter reduction of said plug in the vicinity of saidhousing edge.

5. Tight electric connector according to claim 1, wherein said recess isformed in said housing by machining the edge of said housing about theperiphery of said plug.

6. Tight electric connector according to claim I, wherein said stud iscylindrical.

7. Tight electric connector according to claim 1, wherein the contactsurfaces of the studs of each of said connection elements are planesurfaces and the studs are made conducting material.

8. Tight electric connector according to claim 1 for establishingelectrical connections between two connecting parts of large size, eachconnection element of said connector being carried on one of theconnecting parts to be assembled, wherein an elastic device is interposed between at least one of the connection elements and theconnecting part carrying said element for biasing the connection elementtoward the other connecting part to be assembled.

9. Tight electric connector according to claim l, wherein said plug andsaid stud are connected by vulcanization.

l0. Tight electric connector according to claim I wherein the ratio ofthe protrusion height of the conducting stud above the plug to theprotrusion height of the plug above the housing of the conducting studhas a value between 0.25 and 0.5.

11. Tight electric connector according to claim 10 wherein said ratiohas a value close to 0.33.

12. Tight electric connector according to claim 1 wherein the assemblingclearance between the plug and its housing in said casing is between 0and 0.l mm.

13. Tight electric connector according to claim 12 wherein saidclearance is between 0 and 0.05 mm.

14. A tight electric connector formed of at least one pair of connectormembers each comprising a casing wherein is housed a plug of deformableinsulating material, substantially incompressible, comprising aconducting stud protruding from the plug free surface, the stud having aconical shape with an increasing diameter towards the inside of the plugand being extended by a cylindrical portion of a diameter lower than thegreater diameter of the conical portion, the electrical connectionresulting from the mere application of the connection member studs oneach other in a position of closeness of said members, by pressing saiddeformable plugs against each other, wherein the free surface of thedeformable plug of each connection member protrudes from its housingabove the edge thereof and wherein a recess is arranged about the plugin its housing, close to the edge thereof, in order to leave a space forthe flow of said deformable material which results from the pressing ofsaid two members against each other, thereby ensuring the sealing andelectrical insulation about each conducting stud.

15. A tight electric connector formed of at least one pair of connectormembers each comprising a casing wherein is housed a plug of deformableinsulating material, substantially incompressible, comprising aconducting stud protruding from the plug free surface, the electricalconnection resulting from the mere application of the connection memberstuds on each other in a position of closeness of said members, bypressing said deformable plugs against each other, the contact surfaceof the stud of one of said connection members is conical and the contactsurface of the stud of the other is flat, wherein the free surface ofthe deformable plug of each connection member protrudes from its housingabove the edge thereof and wherein a recess is arranged about the plugin its housing, close to the edge thereof, in order to leave a space forthe flow of said deformable material which results from the pressing ofsaid two members against each other, thereby ensuring the sealing andelectrical insulation about each conducting stud.

16. A tight electric connector according to claim 15 wherein said studhaving a conical contact surface is made of a conducting material of agreater hardness than that of which is made the stud having a planesurface.

17. Tight electric connector formed of two connection members havingeach an insulating plug of deformable material housed in an individualcasing and projecting beyond the casing end surface, a stud embeddedinto said plug and projecting beyond the end surface of said plug, andan annular recess provided in at least one of said plug and said casingproximate to and extending below the casing end surface forming a spacefor the flow of the plug insulating material, occurring when the twoconnection members are pressed against each other.

1. A tight electric connector comprising two connection elements, eachhaving at least one conducting stud embedded in a plug of deformable andsubstantially incompressible insulating material, the conducting studprotruding from the plug free surface, the electrical connectionresulting from the contacting of the conducting studs at a closeposition of said connection elements, each stud being provided with anindividual housing for the plug in which said stud is embedded, the freesurface of the deformable plug protruding from its housing above theedge thereof and having a recess arranged at the periphery of the plugclose to and extending below the edge of the housing to provide for theflow of said deformable material both into the recess and about the studas a result of the pressing of said two connection elements against eachother such that a seal and electrical insulation is provided about eachconducting stud.
 2. Tight electric connector according to claim 1, theplug wherein is made of substantially incompressible elastomer whosehardness degree, expressed in shore units, is between 50 and
 75. 3.Tight electric connector according to claim 1 wherein the plug is madeof substantially incompressible elastomer whose hardness degree,expressed in shore units, is between 60 and
 65. 4. Tight electricconnector according to claim 1, wherein said recess is formed by adiameter reduction of said plug in the vicinity of said housing edge. 5.Tight electric connector according to claim 1, wherein said recess isformed in said housing by machining the edge of said housing about theperiphery of said plug.
 6. Tight electric connector according to claim1, wherein said stud is cylindrical.
 7. Tight electric connectoraccording to claim 1, wherein the contact surfaces of the studs of eachof said connection elements are plane surfaces and the studs are madeconducting material.
 8. Tight electric connector according to claim 1for establishing electrical connections between two connecting parts oflarge size, each connection element of said connector being carried onone of the connecting parts to be assembled, wherein an elastic deviceis interposed between at least one of the connection elements and theconnecting part carrying said element for biasing the connection elementtoward the other connecting part to be assembled.
 9. Tight electricconnector according to claim 1, wherein said plug and said stud areconnected by vulcanization.
 10. Tight electric connector according toclaim 1 wherein the ratio of the protrusion height of the conductingstud above the plug to the protrusion height of the plug above thehousing of the conducting stud has a value between 0.25 and 0.5. 11.Tight electric connector according to claim 10 wherein said ratio has avalue close to 0.33.
 12. Tight electric connector according to claim 1wherein the assembling clearance between the plug and its housing insaid casing is between 0 and 0.1 mm.
 13. TighT electric connectoraccording to claim 12 wherein said clearance is between 0 and 0.05 mm.14. A tight electric connector formed of at least one pair of connectormembers each comprising a casing wherein is housed a plug of deformableinsulating material, substantially incompressible, comprising aconducting stud protruding from the plug free surface, the stud having aconical shape with an increasing diameter towards the inside of the plugand being extended by a cylindrical portion of a diameter lower than thegreater diameter of the conical portion, the electrical connectionresulting from the mere application of the connection member studs oneach other in a position of closeness of said members, by pressing saiddeformable plugs against each other, wherein the free surface of thedeformable plug of each connection member protrudes from its housingabove the edge thereof and wherein a recess is arranged about the plugin its housing, close to the edge thereof, in order to leave a space forthe flow of said deformable material which results from the pressing ofsaid two members against each other, thereby ensuring the sealing andelectrical insulation about each conducting stud.
 15. A tight electricconnector formed of at least one pair of connector members eachcomprising a casing wherein is housed a plug of deformable insulatingmaterial, substantially incompressible, comprising a conducting studprotruding from the plug free surface, the electrical connectionresulting from the mere application of the connection member studs oneach other in a position of closeness of said members, by pressing saiddeformable plugs against each other, the contact surface of the stud ofone of said connection members is conical and the contact surface of thestud of the other is flat, wherein the free surface of the deformableplug of each connection member protrudes from its housing above the edgethereof and wherein a recess is arranged about the plug in its housing,close to the edge thereof, in order to leave a space for the flow ofsaid deformable material which results from the pressing of said twomembers against each other, thereby ensuring the sealing and electricalinsulation about each conducting stud.
 16. A tight electric connectoraccording to claim 15 wherein said stud having a conical contact surfaceis made of a conducting material of a greater hardness than that ofwhich is made the stud having a plane surface.
 17. Tight electricconnector formed of two connection members having each an insulatingplug of deformable material housed in an individual casing andprojecting beyond the casing end surface, a stud embedded into said plugand projecting beyond the end surface of said plug, and an annularrecess provided in at least one of said plug and said casing proximateto and extending below the casing end surface forming a space for theflow of the plug insulating material, occurring when the two connectionmembers are pressed against each other.